Cellulose-containing articles and method of producing such articles



Patented Oct. I3, 1931 UNITED STATES JOHN SHIRLEY LITTLE, LA GRANGE, I

PATENT OFFICE.-

LLINOIB, ASBIGNOB TO WESTERN ELECTRIC I COMPANY, INCORPORATED, OF NEW YORK, N. 'Y., A GOBIORATION 01' NEW YORK OELIIULOSEFCONTAIKING ARTICLES AND METHOD OF PRODUCING SUCH ARTICLES Application fled February 11,1928. Serial No. 253,570.

This invention relates to cellulosecontaining articles and methods of producmg' such articles. Y l

Objects of the invention are the provislon 5 of cellulose-containing articles having electrical and mechanical properties which render them particularly suitable for insulating urposes and the provision of a s1mple, efective, and economical method of producing such articles.

In accordance with the general features of the invention as embodied in one form thereof, a fibrous material, such as paper pulp which contains cellulose, is thorough beaten in the presence of water until 1t ecomes highly hydrated or gelatinized. The resulting material, either alone or mixed with a fillor and/or a waterproofing material, is then extruded-into the form desired and dried slowly under controlled conditions to prevent the formation of cracks due to shrlnk- Other objects and features of the invention will be apparent from the following detailed description of the invention andthe accompanying drawings, in which Flg. 1 is a vertical, longitudinal cross sectional view of an extrusion apparatus for use in making articles in accordance with the invention and which may be used in practicing the method, and

ig. 2 is a similar view of the extrusion machine adapted for use in making articles of another type. I

In the drawings wherein like reference numerals are employed to denote similar parts in the various gures, Fig. 1 illustrates an extrusion apparatus by means of which tubes or other hollow articles made of cellulosecontaining material may be made in accordance with the invention. In this figure, the numeral 1 indicates a base plate which supports a receptacle or chamber 2 which may be filled with a supply of a treated fibrous or pulpous material and a jacketed die member 3 is threaded into the wall of the cham- .ber. Threaded into the chamber wall opposite to and extendin partly into the die 3 is a hollow, truncate -cone-sha ed core 5 designed to receive a series of ro s or mandrels 6-6. A plunger 7 actuated by hydraulic or any other suitable means serves to extrude the treated fibrous or pulpous materialfrom the chamber 2 through the die member 3,

around the end of the core 5, and over the rods or mandrels 6-6. Steam or other suitableheatmg agents may be passed through the acket of the die member 3' by means of the entrance and exit pipes 8 and 9, respectlvely, so that the material passing from the chamber 2 may be subjected to a substantially constant predetermined temperature wh le passing through the die member 3. To

assist 1n pressing the material, the die 3 is so constructed that the diameter of the openlng therethrough decreases adually from the inner end thereof outwar l j until a point near the outer end of the die is reached when the diameter of the opening becomes constant.

The machine illustrated in Fig. 1 may be modified, as shown in Fig. 2, for manufacturin rods, instead of tubes'or other hollow artic es, by removing the hollow core member 5 and substituting a threaded plug 10 therefor. When the extrusion apparatus is thus modified, the treated material may be forced through the die member 3 as a homogeneous cylindrical mass without a central opening.

In the manufacture of articles in accordance with the preferred embodiment of the invention, paper pulp or other cellulose-containing material is thorou hly beaten in water until it becomes high y hydrated or gelatinized. Satisfactory results have been obtained by beatin about four to six parts of paper pul in a out ninety-six to ninetyfour parts 0 water in a ball mill, beater or refiner for about forty-eight hours or more when the material loses substantially all of its fibrous nature and becomes substantially structureless and gelatinized due to the highly hydrated state which it then assumes. The thus treated material is then placed in the cylinder 2 of the extrusion apparatus and formed into either tubes or rods which are cut into suitable length as they emerge from the apparatus, after which the rods or tubes are dried. Since the material tends to shrink considerably during the drying operation, 100

have been obtained by slowly drying the ma terial in a humid atmosphere over an extended period of time which varies with the size and shape of the article produced.

Instead of making the articles of the hydrated or gelatinized pulp alone, variousother ingredients such as filling and/0r waterproofing or be mixed therewith to facilitate extrusion, to reduce shrinkage and to render the final product more waterproof. For exam le, the

ydrated or gelatinized pulp produced as described herembefore may e mixed with a quantity of a filling material, such as clay, suflicient to alter the compositionof the treated pulp so that the Water content of the mixture is about 80 per cent of the total composition. The resulting mixture may then be extruded and dried in a manner similar to that described above for the pure treated pulp. Other suitable filling materials which may be used instead of cl'a are wood flour, plaster of Paris, pulverize soapstone, chalk and other inert substances.

Instead of employing a filling material with the hydrated or gelatinized pulp, the material may be mixed with other materials which tend to harden or waterproof it.

Among such materials are viscose, solutions of cellulose acetate, solutions of zinc chloride,

etc. For example, paper pulp may be beaten in Water until 1t is highly hydrated or gelatinized and the resulting material dehydrated until the water content is about 7 0 per cent of the total composition. A suflicient quantity of a 10 per cent viscose solution is then added to this material to bring the total liquid content of the resulting mixture up to 80 per cent, and the resulting mass of material is then extruded intothe desired shape. The extruded article is then treated with one of the materials Well known in the art, such as an acid bath, to set or precipitate the Viscose, after which the article is dried under controlled conditions in the manner described previously.

It is also possible to produce satisfactory articles by omploving with the gelatinized material both a filling material, such as clay, and a waterproofing material, such as viscose.

' In any case, when the hydrated or gelatinized has material is employed in combination with other materials, the proportions of the other materials are so arranged that the liquid conardening materials, may

cordance with the invention, it is to be understood that other cellulose-containing materials, such as cotton, starch, etc., may be employed with satisfactory results and that the invention is limited only by the spirit and sec 7, pi the annexed claims, v a

rtigleg pr'edqced "in aepordbnee with the 1nvent1on as descri a bye are very dense and li'dfnlike in character and have electrical andmechanical pm ertieswhichrender them particularly euitab e-tor insulating purposes.

What is'claimed is: v 1. A 'm'e'thbd of-"prod'ucin'g' articles, which consists workin four to six parts of fibrous 'inaterial inirinet -six to ninet -four parts ofwater until it ecomes hi h-fy hyrated-,'addiiig a'suflicient quantityo a lling material thereto' to alter the water content of the mixture to about 80%, and forming the resulting mixture into'an article of the de-- sired shape. v z

, 2, A method of producingarticles, which consists in working four 'to six parts of fibrous material in ninet -six to ninet -four parts of Water until it ecomes high y hyrated dehydrating the resulting mixture until the water content is about of the total mixture, adding a sufficient quantity of a Waterproofing material thereto'tmbring the liquid content of the mixture up to 80%, and formin the resulting mixture into an article ofthe esire'd sha e.

3. A methodof producing articles, which consists in working four to six parts of fibrous material in ninet -'six to ninet -four parts of water until it ecomes 'hi hi hydrated, adding sufiicient quantities 0% a lling material and a waterproofing material thereto to bring the li uid content of'themixture up to 80%, and ormin the-resulting mixture into an article of the desired shape.

4. A method, of producing. articles, which consists in working four to six parts of fibrous material in ninety-six to ninety-four parts of water until it becomes hi hly hydrated, adding a suflicient quantity of a filling material theretotoalterthe Water content of the mixture to aboutf80,%',' forming the resulting mixture into an articleof the desired shape, 'and drying the article'in a humid atmosphere to minimize {the formation of shrinkage cracks.

5. A-method of producing articles, which consists. in working four to 'six .parts .of fibrous material in .ninet -six 'to ninet four parts of water until it ecomes high y hydrated; dehydrating the resulting mixture until the water content is about 70% of the total mixture, adding a sufiicientquantity'of a water-proofing material thereto to bring the liquid content of the mixure up to 80%, forming the resulting mixture into an article too llO

of the desired shape, anddrying the article in a humid atmosphereito, minimize-the formation of shrinkagecracks,

6. A method of producing articles, which consists in working four to six parts of fibrous material in ninety-six to ninetffour parts of water until it becomes high hydrated, adding sufiicient quantities of a lling material and a waterproofing material thereto to bring the liquid content of the mixture up to 80%, forming the resulting mixture into an article of the desired shape, and drying the article in a humid atmosphere to minimize the formation of shrinkage cracks.

In witness whereof, I hereunto subscribe my name this 31st day of January A. 1)., 1928.

JOHN SHIRLEY LITTLE. 

